Osteoporotic and non-osteoporotic vertebral body compression fractures are currently treated with vertebroplasty and kyphoplasty. See, G. Lewis, J Biomed Mater Res Part B: Appl Biomater 76(2): 456-468, 2006.
In vertebroplasty, an acrylic cement (e.g., a monomeric cement such as methyl methacrylate cement) is injected through a small hole in the skin (i.e., percutaneously) into a fractured vertebra to stabilize it. Kyphoplasty involves placement of a balloon into a collapsed vertebra before the injection of bone cement to stabilize the fracture.
One of the common risks associated with both vertebroplasty and kyphoplasty is leakage of acrylic cement to the outside of the vertebral body, causing infection, bleeding, numbness, tingling, headache, paralysis, heart damage, lung damage, and even death. Also, polymers formed of certain monomeric acrylic cements used in vertebroplasty and kyphoplasty do not promote growth of new bone tissues due to lack of adequate porosity and biodegradability.
For these and other reasons, there is a need for new approaches to placing into defected bones (e.g., fractured vertebrae) a biocompatible material that not only has little or no toxicity but also has an adequate porosity to allow bone growth and thus accelerates bone healing.